This invention relates to postage indicia printed on mail items and to the provision of security and authentication of said indicia.
Postage meters have been utilized over a long period to print postage indicia on mail items, the postage indicia indicating that postage has been applied to the mail item and that accounting has been effected in respect of the applied postage. Known postage meters include an electronic circuit for carrying out accounting functions in relation to amounts of postage charges applied to mail item. The electronic circuit receives an input of a desired postage charge to be applied to a mail item, carries out accounting in respect of the required postage charge and then operates a printer of the postage meter to print a postage indicium on the mail item. Generally the postage indicium includes at least the postage charge, the date on which the indicium is printed and an identification of the postage meter.
Previously, the printer of the postage meter comprised a rotatable drum printer in which a die plate carried by the drum printed fixed invariable information of the indicium and settable print wheels carried by the drum printed variable information of the indicium. The fixed invariable information comprises a graphical pattern, a meter identification number and the originating postage region for the mail. The variable information comprises an amount of the postage charge and the date of printing the indicium.
The postage meter is constructed in a secure manner by being housed in a secure housing and the printing means which prints the indicium is constructed to work integrally with the meter and also is secure. Accordingly the indicia is printed under conditions of security and attempts to operate the meter and printer in a fraudulent manner in which indicia are printed in respect of postage amounts for which accounting has not been effected are prevented.
However in order to provide additional security with respect to the postage amounts applied to mail items it is desirable that the indicia on the mail items include authenticating information whereby the authenticity of the indicia can be verified. By including this authenticating information it is possible, by examination of indicia on mail items, to detect indicia which are not genuine and purport to represent postage charges. No accounting for the postage charges represented by such non-genuine indicia will have been effected so that such indicia have been produced in a manner which results in fraud on the postal authority or other carrier.
Postage meters currently available are provided with a digital printer in place of the drum printer. The digital printer is controlled by the electronic circuit of the postage meter to print in a series of cycles a pattern of dots to form the complete indicium. It will be appreciated that, whereas the indicium printed by the drum printer of earlier postage meters is invariable apart from the value of postage charge and date, the digital printer of currently available postage meters is capable of printing an indicium containing significantly more variable information. Due to the increased flexibility and capability of digital printers as compared with drum printers it is possible to print additional information in the indicium which can be utilised to authenticate the indicium whereby indicia printed in an unauthorised manner can be recognised and differentiated from indicia printed an unauthorised manner by an unauthorised postage meter.